Method and apparatus for enlarging DVB-CI functionality by enabling a direct access to the conditional access module

Abstract

The invention is to be used in the Digital Video Broadcasting—Common Interface environment for accessing the Conditional Access Module (CAM). The host application handles objects of the Conditional Access (CA) through a private Application Program Interface (API). Each CAM may have its own private CA API but the data channel remains identical whatever the CAM is. This new mode coexists with the two already defined modes: low level Man Machine Interface, and high level Man Machine Interface. If a Set top Unit “understands” the private CA Application Program Interface (API), then it may access the features of the plugged CA through its private CA API Protocol. Otherwise, it remains on the standard API. With this extension, an STU can have a Conditional Access User Interface which perfectly fits into the overall User Interface of the STU. Thus b broadcaster can ensure that its look and feel are respected on its STUs. A manufacturer can build an STU especially optimized for a given or a plurality of Cas but still able to run other CAs.

What is claimed is:  
     
       1. A method for allowing communications exchange between at least one Conditional Access Module and a user interface of a multimedia device in a communications system by enabling a direct access to said at least one conditional access module, said communication system using a standard application program interface protocol and a private application program interface protocol; 
       wherein said method comprises the steps of:  
       transmitting a first message from said conditional access module to said user interface containing predetermined parameters, wherein said parameters are dedicated to said private application program interface protocol;  
       checking if said user interface is matching said parameters;  
       responding with a second message from said user interface to said conditional access module, said second message containing a result of the matching between the Conditional Access Module and the user interface parameters; and  
       in response to said second message, selecting said private protocol or said standard protocol.  
     
     
       2. The method of  claim 1  wherein said first message defines a predetermined format for the communications exchange between said Conditional Access Module and said user interface. 
     
     
       3. The method of  claim 1  wherein the parameters of said first message contain at least the indication of the Conditional Access Module identification, the manufacturer name or the version of the conditional access program. 
     
     
       4. The method of  claim 1  wherein before transmitting said first message, said method further comprises the steps of: 
       determining if said conditional access module contains a private application program interface protocol; and  
       determining if said multimedia devices has a dedicated user interface using said private application program interface protocol.  
     
     
       5. The method of  claim 1  wherein in case of private protocol selection the following communication exchange between said user interface and said conditional access module uses predefined data formats regardless of their contents. 
     
     
       6. The method of  claim 5  wherein said predefined data formats are used either by said conditional access module or said user interface for requesting information, for answering in a bi-directional mode, or for notifying information to said conditional access module or said user interface. 
     
     
       7. An apparatus for allowing communications exchange between at least one Conditional Access Module and a user interface of a multimedia device in a communications system by enabling a direct access to said at least one conditional access module, said communication system using a standard application program interface protocol and a private application program interface protocol; 
       wherein said apparatus comprises:  
       means for transmitting a first message from said conditional access module to said user interface containing predetermined parameters, wherein said parameters are dedicated to said private application program interface protocol;  
       means for checking if said user interface is matching said parameters;  
       means for responding with a second message from said user interface to said conditional access module, said second message containing the result of the matching between the Conditional Access Module and the user interface parameters; and  
       means for selecting said private protocol or said standard protocol according to said second message.  
     
     
       8. The apparatus of  claim 7  wherein said first message defines a predetermined format for the communications exchange between said Conditional Access Module and said user interface. 
     
     
       9. The apparatus of  claim 7  wherein in case of private protocol selection the following communications exchange between said user interface and said conditional access module uses predefined data formats regardless of their contents. 
     
     
       10. The apparatus of  claim 7  wherein said multimedia device is a set top unit connected to a display device.